Radio communication using a plurality of selected antennas

Abstract

The invention relates to a method for radio communication using a plurality of antennas, and to an apparatus for radio communication using a plurality of antennas. An apparatus for radio communication of the invention comprises: 4 antennas; a radio device; an antenna tuning apparatus having 2 antenna ports and 2 radio ports; a switching unit comprising 4 input ports each coupled to one of the antennas through a feeder, and 2 output ports, the switching unit operating in an active configuration in which it provides a path between any one of the output ports and one of the input ports, the active configuration being determined by a configuration instruction generated by the radio device; and a tuning control unit, the tuning control unit receiving a tuning instruction generated by the radio device, the tuning control unit delivering a plurality of tuning control signals to the antenna tuning apparatus.

The invention claimed is: 
     
       1. A method for radio communication by an apparatus including N antennas, the method comprising:
 generating, by a radio communication unit, a configuration instruction and a tuning instruction, and transmitting, by the radio communication unit, the configuration instruction to a switch and the tuning instruction to a tuner; 
 selecting, by the switch comprising N input ports and n output ports, n antennas among the N antennas based on the configuration instruction, and providing, by the switch, a path between an output port of the selected n output ports and an input port of the N input ports, the input port being coupled to antennas of the n selected antennas, where N is an integer greater than or equal to 3, each of the N antennas to be operated at a frequency in a frequency band, n being an integer greater than or equal to 2 and less than or equal to N minus 1, each of the N input ports being coupled to one of the N antennas; and 
 coupling, by an antenna tuning apparatus comprising n antenna ports, m radio ports and p adjustable impedance devices, the n output ports to the n antenna ports, where m is an integer greater than or equal to 2 and where p is an integer greater than or equal to 2m and each of the p adjustable impedance devices has a reactance being adjustable based on the tuning instruction received from the tuner. 
 
     
     
       2. The method of  claim 1 , wherein the path is a path between the output port of the n output ports and only one input port of the N input ports. 
     
     
       3. The method of  claim 2 , wherein the antenna tuning apparatus includes each of n antenna tuning apparatus units comprising one of the n antenna ports, one of the m radio ports, or at least two adjustable impedance devices. 
     
     
       4. The method of  claim 2 ,
 wherein the tuning instruction comprises a function of one or more quantities indicating a channel matrix. 
 
     
     
       5. The method of  claim 2 ,
 wherein the tuning instruction is a function of q real quantities based on an impedance matrix of the m radio ports, where q is an integer greater than or equal to m. 
 
     
     
       6. The method of  claim 2 , further comprising:
 estimating, by a localizer, a plurality of localization variables to determine the configuration instruction, 
 wherein each of the localization variables is determined based on a distance between a part of a human body and a zone of the radio communication unit. 
 
     
     
       7. The method of  claim 6 , wherein the configuration instruction is determined from a set of pre-defined configuration instructions stored in a lookup table, based on the localization variables and on frequencies used for the radio communication with the N antennas. 
     
     
       8. The method of  claim 1 , wherein, when an impedance matrix of the n antenna ports is equal to a diagonal impedance matrix at the frequency in the frequency band, an impedance matrix of the m radio ports is determined based on a reactance of one of the p adjustable impedance devices. 
     
     
       9. The method  claim 8 , wherein at least one non-diagonal entry of the impedance matrix of the m radio ports is determined based on at least one reactance of the p adjustable impedance devices. 
     
     
       10. An apparatus comprising N antennas, the apparatus comprising:
 the N antennas, where N is an integer greater than or equal to 3, each of the N antennas to be operated at a frequency in a frequency band; 
 at least one processor of a radio communication unit, configured to generate a configuration instruction and a tuning instruction, and transmit the configuration instruction to a switch and the tuning instruction to a tuner; 
 a switch comprising N input ports and n output ports, configured to select n antennas among the N antennas based on the configuration instruction, and provide a path between an output port of the selected n output ports and an input port of the N input ports, the input port being coupled to antennas of the n selected antennas, where n is an integer greater than or equal to 2 and less than or equal to N minus 1, each of the N input ports being coupled to one of the N antennas; and 
 an antenna tuning apparatus comprising n antenna ports, m radio ports and p adjustable impedance devices, configured to couple the n output ports to the n antenna ports, where m is an integer greater than or equal to 2, p is an integer greater than or equal to 2m, each of the p adjustable impedance devices has a reactance being adjustable based on the tuning instruction received from the tuner, 
 wherein the tuner is configured to:
 receive the tuning instruction from the at least one processor, and transmit the tuning instruction to the antenna tuning apparatus. 
 
 
     
     
       11. The apparatus of  claim 10 , wherein the path is a path between the output port of the n output ports only one input port of the N input ports. 
     
     
       12. The apparatus of  claim 11 , wherein at least one non-diagonal entry of the impedance matrix of the m radio ports is determined based on at least one reactance of the p adjustable impedance devices. 
     
     
       13. The apparatus of  claim 12 , wherein at least one non-diagonal entry of the impedance matrix of the m radio ports is determined based on at least one reactance of the p adjustable impedance devices. 
     
     
       14. The apparatus of  claim 11 , wherein the antenna tuning apparatus each of n antenna tuning apparatus units comprising one of the n antenna ports, one of the m radio ports, or at least two adjustable impedance devices. 
     
     
       15. The apparatus of  claim 11 , wherein the tuning instruction comprises a function of one or more quantities indicating a channel matrix. 
     
     
       16. The apparatus of  claim 11 , wherein the tuning instruction being a function of q real quantities based on an impedance matrix of the m radio ports, where q is an integer greater than or equal to m. 
     
     
       17. The apparatus of  claim 11 , further comprising:
 a localizer configured to estimate a plurality of localization variables to determine the configuration instruction, 
 wherein each of the localization variables is determined based on a distance between a part of a human body and a zone of the radio communication unit. 
 
     
     
       18. The apparatus of  claim 17 , wherein the configuration instruction is determined from a set of pre-defined configuration instructions stored in a lookup table, based on the localization variables and on the frequencies used for radio communication with the N antennas.